The two met in Utah earlier this month, fueling speculation that they discussed the 2016 contest. Party pundits had feared pitting the two candidates against one another would divide the Republican establishment. (Bush, however, told reporters they “put aside ... awkward” talk of a potential match-up.)

The Florida governor wasn’t the only likely 2016 candidate to weigh in on Romney’s announcement.

Sen. Marco Rubio, R-Fla., who was rumored to be in the running to be Romney’s vice presidential nominee in 2012, said in a statement to ABC News, “Over the past two years, there hasn't been a day when I didn't think that Mitt Romney would have been a better president than Barack Obama.”

“I’ve enjoyed getting to know Mitt and campaigning for him, was grateful for his support in my Senate race, and I know what a difficult decision this must be given his love of our country,” he added. “He certainly earned the right to consider running, so I deeply respect his decision to give the next generation a chance to lead.”

Wisconsin Gov. Scott Walker said he spoke with Romney this afternoon to thank him "for his interest in opening the door for fresh leadership in America."

Had a great conversation w/ @MittRomney. He's a good man. Thanked him for his interest in opening the door for fresh leadership in America.

Democrats Sound Off:

Democrats, too, were generally less effusive about Romney.

At a Democratic retreat in Philadelphia today, according to The Washington Post, House Minority Leader Nancy Pelosi, D-Calif., called Romney a “wonderful American,” and added, “I don’t want to make a joke about his candidacy.”

Other Democrats chimed in on Twitter:

Congratulations to Mitt Romney for finally saying something the American people want to hear.